Cellulose ethers

ABSTRACT

A cellulose ether which has from 4,000 to 10,000 anhydroglucose repeat units and is substituted with (a) on the average from 0.0003 to 0.08 moles, per mole of anhydroglucose unit, of a substituent comprising an alkyl or arylalkyl group having from 8 to 24 carbon atoms and (b) a substituent having the formula II wherein R 5 , R 6  and R 7  each independently are —CH 3  or —C 2 H 5 , R 8  is —CH 2 —CHOH—CH 2 — or —CH 2 CH 2 , A z−  is an anion, and z is 1, 2 or 3 is useful in hair and skin care compositions.

FIELD OF THE INVENTION

The present invention relates to cellulose ethers comprising ahydrophobic substituent and a cationic substituent, their production andtheir use in personal care compositions.

BACKGROUND OF THE INVENTION

Cellulose ethers comprising a hydrophobic substituent and/or a cationicsubstituent have been known since many years.

U.S. Pat. No. 3,472,840 discloses quaternary nitrogen-containingcellulose ethers and their use as flocculents for paper pulp, coal dustor silica or clay or as a retention aid in the manufacture of paper.

U.S. Pat. No. 4,663,159 discloses hydrophobically substitutedwater-soluble cationic polysaccharides. The hydrophobic substituent is aquaternary substituent which contains nitrogen and an alkyl group of atleast 8 carbon atoms. The water-soluble polysaccharides are typicallyhydroxyethyl celluloses which have on the average about 2 moles ofhydroxyethyl substituent per mole of polysaccharide repeat unit. Thedisclosed hydroxyethyl celluloses have a molecular weight to provide a 2weight percent Brookfield viscosity between 20 and 500 cps, whichcorresponds to about 400-1,600 anhydroglucose repeat units. Thehydrophobically substituted water-soluble polysaccharides are useful inhair and skin treatment formulations, such as shampoos and hand lotions.However, it would be desirable to improve the substantivity of thesepolymers, that means the retention of the polymers at a solid surface,such as hair or skin, when aqueous compositions containing suchpolymers, are applied to hair or skin.

U.S. Pat. No. 5,407,919 discloses double substituted cationic celluloseethers substituted with greater than 0.11 to 0.25 moles, per mole ofanhydroglucose unit, of a hydrophobic substituent and with from 0.05 to0.50 moles, per mole of anhydroglucose unit, of a cationic substituent.The cationic cellulose ethers have enhanced viscosity and foaming, butpoor substantivity. Unfortunately, typical shampoo formulationscontaining these cationic cellulose ethers are very viscous, to thepoint of forming gels, which makes them impractical.

Accordingly, it would be desirable to provide new cellulose ethers whichare useful in personal care compositions, such as hair or skin carecompositions. It would be particularly desirable to provide newcellulose ethers which provide hair or skin care compositions with anoptimized viscosity and/or good substantivity. It is a preferred objectof the present invention to provide new cellulose ethers which areuseful for preparing hair care compositions with good wet and drycombability and/or a good wet and dry feel. It is another preferredobject of the present invention to provide new cellulose etherderivatives for preparing skin care compositions which comprise amoisturizing agent, particularly for preparing skin care compositionswhich leave a high level of moisturizing agent, such as sunflower seedoil on the skin.

SUMMARY OF THE INVENTION

One aspect of the present invention is a cellulose ether which has from4,000 to 10,000 anhydroglucose repeat units and which is substitutedwith

(a) on the average from 0.0003 to 0.08 moles, per mole of anhydroglucoseunit, of a substituent comprising an alkyl or arylalkyl group havingfrom 8 to 24 carbon atoms and

(b) a substituent having the formula II[R⁵R⁶R⁷R⁸N⁺](A^(z−))_(1/z)  (II)wherein

-   R⁵, R⁶ and R⁷ each independently are —CH₃ or —C₂H₅,-   R⁸ is —CH₂—CHOH—CH₂— or —CH₂CH₂—-   A^(z−) is an anion, and-   z is 1, 2 or 3.

Another aspect of the present invention is a process for producing theabove-mentioned cellulose ether. The process comprises the step ofreacting a cellulose ether having from 4,000 to 10,000 anhydroglucoserepeat units with

(a) a compound comprising an alkyl or arylalkyl group having from 8 to24 carbon atoms and being selected from the group consisting ofglycidylethers, alpha-olefin epoxides, alkylhalides compounds of formulaIa and mixtures thereofR¹R²R¹⁰R⁴N⁺(A^(z−))_(1/z)  (Ia)wherein

-   R¹ and R² each independently are —CH₃ or —C₂H₅,-   R⁴ is an alkyl or arylalkyl group having from 8 to 24 carbon atoms,

-   A^(z−) is an anion, and-   z is 1, 2 or 3; and

(b) a compound of formula IIa[R⁵R⁶R⁷R⁹N⁺](A^(z−))_(1/z)  (IIa)wherein

-   R⁵, R⁶ and R⁷ each independently are —CH₃ or —C₂H₅,

-   A^(z−) is an anion, and-   z is 1, 2 or 3.

Yet another aspect of the present invention is a personal carecomposition, such as a hair or skin care composition, which comprisesthe above-mentioned cellulose ether.

DETAILED DESCRIPTION OF THE INVENTION

Cellulose ethers suitable for use in accordance with the presentinvention include etherified derivatives of cellulose. Typical celluloseethers include for example, hydroxyethyl cellulose, hydroxypropylcellulose, methyl cellulose, hydroxypropyl methyl cellulose,hydroxyethyl methyl cellulose or hydroxyethyl carboxylmethyl cellulose.Preferred cellulose ethers include hydroxyethyl cellulose andhydroxypropyl cellulose. The most preferred cellulose ethers suitablefor use in accordance with the present invention comprise hydroxyethylgroups. Preferably, these cellulose ethers have an M.S. (hydroxyethyl)of from 1.0 to 3.0, more preferably from 1.5 to 2.5. The M.S.(hydroxyethyl) designates the average number of moles of hydroxyethylgroups which have been attached by an ether linkage per mole ofanhydroglucose unit. The cellulose ethers have at least 4,000anhydroglucose repeat units, preferably at least 4,500 anhydroglucoserepeat units, more preferably at least 5,000 anhydroglucose repeatunits, and most preferably at least 6,000 anhydroglucose repeat units.The cellulose ethers have up to 10,000 anhydroglucose repeat units,preferably up to 9,000 anhydroglucose repeat units and most preferablyup to 8,000 anhydroglucose repeat units. Such cellulose ethers arereadily commercially available. Alternatively, such cellulose ethers canbe prepared from cellulose by methods known to those skilled in the art.

The cellulose ether derivatives of the present invention are celluloseethers which are substituted with a hydrophobic substituent (a) and acationic substituent (b) as described below.

Hydrophobic substituents (a) suitable for use in accordance with thepresent invention comprise an alkyl or arylalkyl group having from 8 to24 carbon atoms, preferably from 10 to 24 carbon atoms, more preferablyfrom 12 to 18 carbon atoms, and most preferably 12 to 15 carbon atoms.As used herein the term “arylalkyl group” means a group containing botharomatic and aliphatic structures. The most preferred aliphatichydrophobic substituent is the dodecyl group, which is most preferablystraight-chained. The hydrophobic substituent is typically cationic ornon-ionic. Many hydrophobe-containing reagents suitable for use ashydrophobic substituents are commercially available. In addition,methods for preparing such hydrophobe-containing reagents, as well asmethods for derivatizing cellulose ethers to comprise such hydrophobicsubstituents, are known to those skilled in the art. Note for example,U.S. Pat. No. 4,228,277 issued Oct. 14, 1980, U.S. Pat. No. 4,663,159,issued May 5, 1987 and U.S. Pat. No. 4,845,175, issued Jul. 4, 1989.

A preferred hydrophobic substituent (a) suitable for use in accordancewith the present invention has the formula (I)R¹R²R³R⁴N⁺(A^(z−))_(1/z)  (I)wherein

-   R¹ and R² each independently are —CH₃ or —C₂H₅,-   R³ is —CH₂—CHOH—CH₂— or —CH₂CH₂—-   R⁴ is an alkyl or arylalkyl group having from 8 to 24 carbon atoms,    and-   A^(z−) is an anion, and-   z is 1, 2 or 3.

Preferably, R¹ and more preferably, both R¹ and R² are —CH₃. Preferably,R³ is —CH₂—CHOH—CH₂—. Preferably, R⁴ is —C_(n)H_((2n+1)), where n isfrom 8 to 24, more preferably from 10 to 18, most preferably 12. A^(z−)is an anion with the valency of z, such as phosphate, nitrate, sulfateor halide. Chloride is the most preferred ion. Z is preferably 1 or 2,more preferably 1. The most preferred hydrophobic substituents (a) arethose wherein two or more, preferably each of R¹, R², R³, R⁴, A^(z−) andz have the mentioned preferred meanings.

Other preferred hydrophobic substituents include those derived fromhydrophobe-containing reagents comprising alkyl or arylalkyl groupshaving from 8 to 24 carbon atoms, preferably from 10 to 24 carbon atoms,more preferably from 12 to 18 carbon atoms, and most preferably 12 to 15carbon atoms. Preferred are glycidyl ethers, such as nonylphenylglycidyl ether or dodecylphenyl glycidyl ether; or alpha-olefinepoxides, such as 1,2-epoxy hexadecane and their respectivechlorohydrins, or alkyl halides, e.g., dodecyl bromide, and mixturesthereof.

The average substitution level of the substituent (a) is at least0.0003, preferably at least 0.0005 moles per mole of anhydroglucose unitand up to 0.08, preferably up to 0.07, and most preferably up to 0.05moles per mole of anhydroglucose unit. More than one particularhydrophobic substituent can be substituted onto the cellulose etherprovided that the total substitution level is within the ranges setforth above.

The cationic substituent (b) suitable for use in accordance with thepresent invention has the formula II[R⁵R⁶R⁷R⁸N⁺](A^(z−))_(1/z)  (II)wherein

-   R⁵, R⁶ and R⁷ each independently are —CH₃ or —C₂H₅,-   R⁸ is —CH₂—CHOH—CH₂— or —CH₂CH₂—-   A^(z−) is an anion, and-   z is 1, 2 or 3.

Preferably, R⁵ is —CH₃. More preferably, R⁵, R⁶ and R⁷ are —CH₃.Preferably, R⁸ is —CH₂—CHOH—CH₂—. A^(z−) is an anion with the valency ofz, such as phosphate, nitrate, sulfate or halide. Chloride is the mostpreferred ion. Z is preferably 1 or 2, more preferably 1. The mostpreferred cationic substituents (b) are those wherein two or more,preferably each of R⁵, R⁶, R⁷, R⁸, A^(z−) and z have the mentionedpreferred meanings.

Methods for preparing cationic substituents (b) such as described above,as well as methods for derivatizing cellulose ethers to contain suchcationic substituents, are known to those skilled in the art. Note forexample, U.S. Pat. No. 4,663,159 issued May 5, 1987.

The average substitution level of the cationic substituent (b) isgenerally from about 0.02 to about 0.9 moles, preferably from about 0.05to about 0.8 moles, more preferably from about 0.1 to about 0.6 moles,most preferably from 0.15 to 0.35 moles of the substituent (b), per moleof anhydroglucose unit. More than one particular cationic substituent(b) can be substituted onto the cellulose ether, but the totalsubstitution level is preferably within the ranges set forth above.

The average weight percent of nitrogen per anhydroglucose repeat unit ispreferably from about 0.2 to about 3.5 percent, more preferably fromabout 0.5 to about 2.5 percent, most preferably from about 0.5 to about2.0 percent.

The most preferred cellulose ethers of the present invention comprise apreferred substituent (a) and a preferred substituent (b) as describedabove in combination, preferably in the preferred weight rangesdisclosed above.

The cellulose ether derivatives of the present invention are typicallywater-soluble. As used herein, the term “water-soluble” means that atleast 1 gram, and preferably at least 2 grams of the cellulose etherderivative are soluble in 100 grams of distilled water at 25° C. and 1atmosphere. The extent of water-solubility can be varied by adjustingthe extent of ether substitution on the cellulose ether and by adjustingthe substitution level of the hydrophobic substituent and the cationicsubstituent. Techniques for varying the water solubility of celluloseethers are known to those skilled in the art.

The cellulose ether derivatives of the present invention preferably havea viscosity of from 1,500 to 350,000 mPa·s, more preferably from 2,000to 150,000 mPa·s, most preferably from 50,000 to 90,000 mPa·s, measuredas a 2 weight percent aqueous solution at 25° C. with a Brookfieldviscosimeter.

The cellulose ether derivatives of the present invention are produced byreacting a cellulose ether having from 4,000 to 10,000 anhydroglucoserepeat units with

(a) a compound which comprises an alkyl or arylalkyl group having from 8to 24 carbon atoms and which is a glycidyl ether, an alpha-olefinepoxide, an alkyl halide, a compound of formula Ia below or a mixturethereof:R¹R²R¹⁰R⁴N⁺(A^(z−))_(1/z)  (Ia)wherein

-   R¹, R², R⁴, A^(z−) and z have the above-mentioned meanings and

(b) a compound of formula IIa[R⁵R⁶R⁷R⁹N⁺](A^(z−))_(1/z)  (IIa)wherein

-   R⁵, R⁶, R⁷, A^(z−) and z have the above-mentioned meanings and

The compounds (a) and (b) can be reacted with the cellulose ether havingfrom 4,000 to 10,000 anhydroglucose repeat units in any order. That is,the compound (a) can be reacted with the cellulose ether prior to,subsequent to, or simultaneously with the compound (b) in a knownmanner. Preferably, the reaction is carried as described in U.S. Pat.No. 5,407,919 while adapting the molar ratio between the cellulose etherand the compounds (a) and (b) to the desired substitution levels.Preferably, the molar ratio between the compound (a) and theanhydroglucose units of the cellulose ether is from 0.002 to 0.4, morepreferably from 0.02 to 0.2. Preferably, the molar ratio between thecompound (b) and the anhydroglucose units of the cellulose ether is from0.1 to 2.0, more preferably from 0.3 to 0.7.

The cellulose ether derivatives of the present invention have a varietyof end-use applications, such as, for example, industrial applicationsand household and personal care applications. Typical industrialapplications include, for example, use as viscosity adjusters orsuspension aids. Typical household and personal care applicationsinclude, for example, pharmaceutical and cosmetic compositions, such ascontraceptive compositions, condom lubricants, vaginal ointments,douches, ophthalmic compositions, cleansers, skin creams, lotions,soaps, shampoos or conditioners.

A preferred end-use application for cellulose ether derivatives of thepresent invention is as a component in a personal care composition whichcomprises the cellulose ether derivative and a personal care ingredient.As used herein, the term “personal care ingredient” includes, but is notlimited to, active ingredients, for example vitamins, silicone oils, sunscreens, as well as solvents, diluents and adjuvants such as water,ethyl alcohol, isopropyl alcohol, higher alcohols, glycerin, propyleneglycol, sorbitol, preservatives, surfactants, menthol, eucalyptus oil,other essential oils, fragrances or viscosity adjusters. Such personalcare ingredients are commercially available and known to those skilledin the art.

The most preferred end-use application for cellulose ether derivativesof the present invention is as a component in hair or skin carecompositions, such as shampoos, conditioners, hand or body lotions,soaps, and body wash formulations.

The amount of the cellulose ether derivatives present in the personalcare composition will vary depending upon the particular composition.Typically, however, the personal cafe composition will comprise fromabout 0.05 to 5 weight percent, more preferably from about 0.1 to 1weight percent of the cellulose ether derivative of the presentinvention, based on the total weight of the personal care composition.

Quite surprisingly, it has been found that at least the preferredcellulose ether derivatives of the present invention generally provideimproved wet comb-ability, improved wet and dry feel, improved siliconedeposition ability and/or improved polymer substantivity, as comparedwith cationic cellulose ether derivatives which do not contain ahydrophobic substituent and the number of anhydroglucose repeat units asdescribed herein.

It has also been found that the cellulose ether derivatives of thepresent invention are very useful in skin care compositions, such ashand or body lotions, soaps, and body wash formulations. Skin carecompositions commonly comprise skin moisturizing agents, such assunflower seed oil. It is highly desirable that much of the moisturizingagent remains on the skin after it has been treated with the skin carecomposition. It has been found that at least the preferred celluloseether derivatives of the present invention are very effective in theproduction of skin care compositions which provide a high deposition ofthe moisturizing agent, such as sunflower seed oil on the skin.

The present invention is illustrated by the following examples which arenot to be construed to limit the scope of the invention. Unlessotherwise indicated, all parts and percentages are by weight.

EXAMPLES

The molecular weights of the hydroxyethyl celluloses below are given asviscosities measured as a 1 or 2 weight percent aqueous solution at 25°C. using a Brookfield LTV viscometer.

The following materials are used in the Examples:

HEC-1: A hydroxyethyl cellulose having a viscosity of 5,700 cps (mPa·s)(1 percent), about 7000 to 8000 anhydroglucose repeat units and anaverage number of moles of hydroxyethyl groups per mole ofanhydroglucose unit, designated as M.S.(hydroxyethyl), of about 2.2.

HEC-2: A hydroxyethyl cellulose having a viscosity of 2,400 cps (mPa·s)(1 percent), about 6500 to 7000 anhydroglucose repeat units and an M.S.(hydroxyethyl) of about 2.2.

HEC-3: A hydroxyethyl cellulose having a viscosity of 5,000 cps (mPa·s)(2percent), about 2500 to 3500 anhydroglucose repeat units and an M.S.(hydroxyethyl) of about 2.2.

HEC-4: A partially water-soluble hydroxyethyl cellulose having aviscosity of 1400 cps (mPa·s) (1 percent), about 7000 to 8000anhydroglucose repeat units and an M.S. (hydroxyethyl) of about 1.4.

HEC-5: A hydroxyethyl cellulose having a viscosity of about 700 cps(mPa·s) (2 percent), about 2500 to 3500 anhydroglucose repeat units andan M.S. (hydroxyethyl) of about 1.5.

Q151: A 70 weight percent aqueous solution of 2,3-epoxypropyltrimethylammonium chloride, commercially available from Degussa Corporation asQUAB™ 151.

Q342: A 40 weight percent aqueous solution of3-chloro-2-hydroxypropyldodecyldimethyl ammonium chloride, commerciallyavailable from Degussa Corporation as QUAB™ 342.

NaOH: A 25 weight percent aqueous solution of sodium hydroxide.

IPA: Isopropyl alcohol.

The properties of the cellulose ether derivatives of the presentinvention are measured as follows:

Nitrogen content, percent N: The average weight percent of nitrogen peranhydroglucose repeat unit is determined analytically by using anautomated Bucbi Kjeldahl distillation unit and titrating with anautomated titrimeter.

The average number of moles of the hydrophobic substituent (a) per moleof anhydroglucose unit is designated as hydrophobic substitution (HS).According to one method the HS is measured using nuclear magneticresonance (1H-NMR, 400 MHz, sodium trimethylsilyl propionate as astandard and deuterium oxide as a solvent at room temperature).

According to another method the HS is calculated based on adetermination of the reaction efficiency of Q342 in reference reactionscarried out under the same reaction conditions as described in Examples1-21 below, but without adding Q151. The percent nitrogen in theresulting cellulose ether derivative which only contains2-hydroxypropyldodecyldimethyl ammonium chloride as hydrophobicsubstituent (a), but no cationic substituent (b) is measured by theKjeldahl method. From the weight percent of nitrogen and the weight ofQ342 added to the reaction mixture per gram of HEC, the reactionefficiency of Q342 is calculated. The following data points (percentN/[Q342/g HEC]) are found: (0.03/0.039); (0.07/0.075); (0.11/0.15);(0.10/0.15); (0.18/0.29); (0.18/0.29); (0.25/0.44); (0.26/0.44);(0.38/0.58); (0.40/0.72); and (0.48/0.84). A linear regression is madebased on these data points. It is found that a linear correlation existsbetween the percent N and the Q342 added to the reaction mixture pergram of HEC. From the percent nitrogen the hydrophobic substitution canbe calculated. Also the Q342 efficiency can be calculated. Since in thereactions of Examples 1-21 most of the Q342 reacts completely beforeQ151 is added, the same reaction efficiency of Q342 is assumed in thereactions of Examples 1-21 as in the reference reactions which arecarried out the absence of Q151. The accuracy of this method iscontrolled in a few examples by determining the HS by 1H-NMR. Asillustrated by Table 2 below, the calculated HS based on efficiencies ofthe above-described reference reactions and the HS determined by 1H-NMRprovide similar results.

The average number of moles of the cationic substituent (b) per mole ofanhydroglucose unit is designated as cationic substitution (CS) and ismeasured using nuclear magnetic resonance (1H-NMR, 400 MHz, sodiumtrimethylsilyl propionate as a standard and deuterium oxide as a solventat room temperature) and/or by calculating the difference between thetotal nitrogen content and the nitrogen content due to the HS.

Viscosity 1 percent: The viscosity of a 1 weight percent aqueoussolution at 25° C. is measured using a Brookfield LTV viscometer at 30rpm (revolutions per minute) and using an appropriate sized spindlelisted in Table 1 below.

Viscosity 2 percent: The viscosity of a 2 weight percent aqueoussolution at 25° C. is measured using a Brookfield LTV viscometer usingspindle No. 4 at the rpm listed in Table 2 below.

A1. Preparation of the Hydroxyethyl Cellulose of Comparative Example A

A reaction vessel equipped with a stirrer, condenser, addition funnels,and nitrogen supply is charged with 41.6 g, on a pure basis, ofhydroxyethyl cellulose (HEC) listed in Table 2 below, and with isopropylalcohol and water in the amounts listed in Table 1 below. After purgingwith nitrogen, a 25 percent aqueous sodium hydroxide solution is added.The weight of sodium hydroxide, calculated as pure product, is listed inTable 1 below. After stirring for 30 minutes, Q151 is added. Its weight,calculated as undiluted 2,3 epoxypropyltrimethyl ammonium chloride islisted in Table 1 below. The reaction mixture is heated to 55° C. andheld there for 120 minutes. After heating, the reaction mixture iscooled and neutralized by adding 2.4 g of acetic acid.

The reaction slurry is filtered and washed once with 400 g of 10 percentaqueous isopropyl alcohol, once with 400 g of 5 percent aqueousisopropyl alcohol, and once with 300 g of anhydrous isopropyl alcohol,and once with 200 g of anhydrous isopropyl alcohol containing 10 ml of40 percent aqueous glyoxal and 10 ml of acetic acid. After drying undervacuum with low heat, 47 g of product containing about 3 percentvolatiles is obtained.

A2. Preparation of the Hydroxyethyl Celluloses of Examples 1-21

A reaction vessel equipped with a stirrer, condenser, addition funnels,and nitrogen supply is charged with 41.6 g, on a pure basis, ofhydroxyethyl cellulose (HEC) listed in Table 2 below, and with isopropylalcohol and water in the amounts listed in Table 1 below. After purgingwith nitrogen, a 25 percent aqueous sodium hydroxide solution is added.The weight of sodium hydroxide, calculated as pure product, is listed inTable 1 below. After stirring for 30 minutes, Q342 is added. Its weight,calculated as undiluted 3-chloro-2-hydroxypropyldodecyldimethyl ammoniumchloride is listed in Table 1 below. The reaction mixture is heated to55° C., and held there for 60 to 90 minutes. While the reaction mixtureis kept at 55° C., Q151 is added. Its weight, calculated as undiluted2,3-epoxypropyltrimethyl ammonium chloride, is listed in Table 1 below.After heating for another 90 to 120 minutes (for a total cook out timeof 180 minutes), the reaction mixture is cooled and neutralized wit 2.2g acetic acid.

The reaction slurry is filtered and washed twice with 300 g of 10percent aqueous isopropyl alcohol, once with 400 g of 10 percent aqueousisopropyl alcohol, and once with 300 g of anhydrous isopropyl alcohol,and once with 200 g of anhydrous isopropyl alcohol containing 10 ml of40 percent aqueous glyoxal and 10 ml of acetic acid. After drying undervacuum with low heat, 47 g of product containing about 3 percentvolatiles is obtained.

TABLE 1 Production of the cellulose ether derivatives (Comp.) GramsGrams Grams Grams Grams Example NaOH Q151 Q342 IPA distilled water A1.32 7.6 0 204 43.5  1 4.12 6.1 24 204 22  2 2.72 6.4 18 204 18  3 2.726.8 12 204 25  4 1.68 7.7 3.1 192 36  5 1.46 7.9 1.2 290 38  6 1.41 7.90.8 190 39  7 1.36 7.9 0.3 190 39  8 1.34 7.9 0.15 190 39  9 2.72 17 12205 24 10 2.72 6.8 12 203 26 11 2.72 9.7 12 204 26 12 2.72 6.8 12 204 2613 1.51 7.8 1.6 190 38 14 2.72 6.5 12 204 26 15 2.72 9.7 12 204 26 162.72 6.5 12 204 26 17 1.51 7.8 1.6 190 37.5 18 2.04 7.3 6.2 204 38 191.41 19 0.8 192 37 20 1.51 19 1.6 192 37 21 1.68 18 3.1 194 34

TABLE 2 Properties of the produced cellulose ether derivatives (Comp.)1% vis- 2% Example HEC % N HS* HS** CS cosity viscosity A HEC-1 0.93 0.00.0 0.19 2460¹⁾ 40,000⁴⁾  1 HEC-1 1.02 0.07 0.07 0.15 4500²⁾ 330,000⁵⁾  2 HEC-1 0.87 0.05 0.06 0.13 4200²⁾ 152,000⁶⁾   3 HEC-1 0.93 0.030 0.0260.16 3070¹⁾ 58,000⁶⁾  4 HEC-1 0.92 0.010 0.010 0.18 2980¹⁾ 69,000⁶⁾  5HEC-1 0.86 0.005 0.003 0.17 3500²⁾ 68,000⁶⁾  6 HEC-1 0.91 0.003 —¹⁰⁾0.18 3600²⁾ 65,000⁶⁾  7 HEC-1 0.86 0.001 —¹⁰⁾ 0.17 3600²⁾ 57,000⁶⁾  8HEC-1 0.90 0.0005 —¹⁰⁾ 0.18 3600²⁾ 62,000⁶⁾  9 HEC-1 1.67 0.035 —¹⁰⁾0.34 2560¹⁾ 50,000⁶⁾ 10 HEC-2 0.90 0.030 —¹⁰⁾ 0.15 1600²⁾ 17,000⁷⁾ 11HEC-3 1.17 0.030 0.024 0.23  285³⁾  3,600⁷⁾ 12 HEC-3 0.92 0.030 0.0220.17  340³⁾  5,000⁷⁾ 13 HEC-3 0.88 0.006 0.003 0.18 —¹⁰⁾  3,400⁷⁾ 14HEC-4 0.93 0.030 —¹⁰⁾ 0.14 6000²⁾ 160,000⁷⁾ 15 HEC-5 1.17 0.030 —¹⁰⁾0.20  620³⁾  8,000⁷⁾ 16 HEC-5 0.96 0.030 —¹⁰⁾ 0.15  670³⁾  9,000⁷⁾ 17HEC-1 0.91 0.006 —¹⁰⁾ 0.18 3000²⁾ —¹⁰⁾ 18 HEC-1 0.87 0.02 —¹⁰⁾ 0.162700²⁾ —¹⁰⁾ 19 HEC-1 1.79 0.003 —¹⁰⁾ 0.40 2000²⁾ 26,000⁴⁾ 20 HEC-1 1.790.006 —¹⁰⁾ 0.40 2000²⁾ 24,500⁴⁾ 21 HEC-1 1.71 0.010 —¹⁰⁾ 0.37 2200²⁾28,000⁴⁾ *Calculated based on efficiencies of reference reactions asdescribed above **Determined by 1H-NMR ¹⁾Spindle No. 3 ²⁾Spindle No. 4³⁾Spindle No. 2 ⁴⁾12 rpm ⁵⁾1.5 rpm ⁶⁾6 rpm ⁷⁾30 rpm ¹⁰⁾not measured

B. Wet Comb-Ability

The wet combing force (WCF) is measured by using the load cell of anInstron Tensile Tester when a comb is pulled through a wet hair tress.The wet comb-ability of a shampoo formulation is calculated as followsin terms of the wet combing end-peak force (WCEPF) reduction of hairtress treated with a shampoo formulation containing a cellulose etherderivative listed in Tables 3-5 below, as compared to hair tress treatedwith a comparative formulation containing the same surfactant but nocellulose ether derivative: % WCEPFReduction=[(WCEPF_(control)−WCEPF_(shampooed))]WCEPF_(control)]×100where control means that the hair tress is treated by the samesurfactant base as in the shampoo formulation but without celluloseether derivative, and shampooed means that the hair tress is treated bythe shampoo formulation comprising a certain amount of a cellulose etherderivative and the same surfactant base as used for control,respectively.

In a first comb-ability test the end-peak combing force reduction of anaqueous shampoo formulation A comprising 15.5 percent sodiumlaureth-2-sulfate (SLES), 2.6 percent disodium cocaamphodiacetate(DSCADA), 0.5 percent of a cellulose ether derivative listed in Table 3below, and the remainder being water, is measured as indicated above andis listed in Table 3 below.

TABLE 3 Comb-ability of shampoo formulation A in relation to HSCellulose End Peak ether of M.S. Force (Comp.) (hydro- 2% ReductionExample HEC % N xyethyl) HS viscosity (%) A HEC-1 0.93 2.2 0.000 40,00010  8 HEC-1 0.90 2.2 0.0005 62,000 16  7 HEC-1 0.86 2.2 0.001 57,000 56 6 HEC-1 0.91 2.2 0.003 65,000 69 17 HEC-1 0.91 2.2 0.006 —*) 83  4HEC-1 0.92 2.2 0.010 69,000 79 18 HEC-1 0.87 2.2 0.02 —*) 72  3 HEC-10.93 2.2 0.030 58,000 78  1**) HEC-1 1.02 2.2 0.07 330,000  0 *)Notmeasured **)Not directly comparable with the other examples because ofthe much higher viscosity

In a second comb-ability test the end-peak combing force reduction of anaqueous shampoo formulation B comprising 14.3 percent sodiumlaureth-2-sulfate (SLES), 2 percent cocoamidopropyl betaine (CAPB), 0.5percent of a cellulose ether derivative listed in Table 4 below, and theremainder being water, is measured as indicated above and listed inTable 4 below.

TABLE 4 Comb-ability of shampoo formulation B Cellulose ether of (Comp.)M.S. End Peak Force Example HEC % N (hydroxyethyl) HS 2% viscosityReduction (%) A HEC-1 0.93 2.2 0.000 40,000 2 8 HEC-1 0.90 2.2 0.000562,000 66 7 HEC-1 0.86 2.2 0.001 57,000 64 6 HEC-1 0.91 2.2 0.003 65,00046 17  HEC-1 0.91 2.2 0.006 —*) 11 *)Not measured

The results in Tables 3 and 4 illustrate that the wet comb-ability of ashampoo formulation can often be significantly improved by incorporatinga cellulose ether derivative of the present invention into the shampooformulation. The optimum level of substitution with the hydrophobicsubstituent (a) depends on the particular shampoo formulation.

In a further test, the wet comb-ability of shampoo formulation A whichcontains various cellulose ether derivatives of different molecularweights, expressed as viscosity of a 2 percent aqueous solution, isevaluated.

As illustrated by the results in Table 5 below, better comb-ability isachieved with cellulose ether derivatives of higher viscosity.

TABLE 5 Comb-ability of shampoo formulation A in relation to molecularweight Cellulose End Peak ether of Force (Comp.) M.S. 2% vis- ReductionExample HEC % N (hydroxyethyl) HS cosity (%) 3 HEC-1 0.93 2.2 0.03058,000 78% 10 HEC-2 0.90 2.2 0.030 17,000 7% 12 HEC-3 0.92 2.2 0.0305,000 0% 11 HEC-3 1.17 2.2 0.030 3,600 21% 16 HEC-5 0.96 1.5 0.030 9,0000% 15 HEC-5 1.17 1.5 0.030 8,000 21% 13 HEC-3 0.88 2.2 0.006 3,400 6%

In a further test, the wet comb-ability of shampoo formulation A whichcontains 0.5 percent or 0.3 percent of various cellulose etherderivatives with a relatively high nitrogen content is evaluated andlisted in Table 6. The results in Table 6 illustrate that even with lowmolecular weight cellulose ether derivatives an improved comb-ability isachieved when the cellulose ether derivatives have a relatively highnitrogen content.

TABLE 6 Comb-ability of shampoo formulation A Cellulose End Peak etherof % cellulose Force (Comp.) M.S. 2% ether in Reduction Example HEC % N(hydroxyethyl) HS viscosity composition (%) B* HEC-1 1.8 2.2 0 13,0000.5% 53 19 HEC-1 1.79 2.2 0.003 26,000 0.5% 73 20 HEC-1 1.79 2.2 0.00624,500 0.5% 79 21 HEC-1 1.71 2.2 0.01 28,000 0.5% 82  9 HEC-1 1.67 2.20.035 50,000 0.5% 85 B* HEC-1 1.8 2.2 0 13,000 0.3% 0 19 HEC-1 1.79 2.20.003 26,000 0.3% 43 20 HEC-1 1.79 2.2 0.006 24,500 0.3% 47 21 HEC-11.71 2.2 0.01 28,000 0.3% 35 *Comparative Example B is HEC-1 quaternizedwith 2,3-epoxypropyltrimethyl ammonium chloride and is commerciallyavailable under the trademark UCARE JR-30 M.

C.) Silicone Deposition Ability

An aqueous shampoo composition is prepared which comprises a) 0.25percent of the cellulose ether derivative of Comparative Example A or ofExample 17 respectively, b) 1 percent of a polydimethylsiloxane,commercially available from Dow Corning as 1664 Emulsion, c) 15.5percent sodium laureth-2-sulfate (SLES) and d) 2.6 percent disodiumcocaamphodiacetate (DSCADA), and the remainder being water.

The silicone deposition ability of a cellulose ether derivative isdetermined by measuring the amount of silicone conditioning ingredientsdeposited on hair from the cellulose ether-containing shampoo. Thesilicone ingredients are firstly extracted off from the hair by asolution comprising 50 volume percent of methylisobutylketone and 50volume percent of toluene. An Atomic Absorption Spectrophotometer isused to detect the silicone concentration of the extracted samplesolution, and then the micro-gram silicone per gram hair is calculated.

When hair is shampooed twice, the cellulose ether derivative of Example17 having a HS of 0.006 can deliver about 30 percent more silicone thanthe cellulose ether derivative of Comparative Example A having an HS of0.000. When hair is shampooed ten times, the cellulose ether derivativeof Example 17 having a HS of 0.006 can deliver about 66 percent moresilicone than the cellulose ether derivative of Comparative Example Ahaving an HS of 0.000.

D) Polymer Substantivity and Build Up

Polymer Substantivity and Build up: The substantivity and build up onhair of a cellulose ether derivative are measured indirectly bydetecting the amount of Lowacene Red 80 (trademark) dye molecules (fromJos. H. Lowenstein and Sons) bound by the cellulose ether derivativedeposited on hair. The cationic cellulose ether derivatives can complexwith the anionic dye of Lowacene Red 80 through both electrostatic andhydrophobic interactions, thus the amount of cellulose ether derivativesdeposited on the shampoo-treated hair tress is proportional to theamount of dye molecules bound by the shampoo-treated hair. Typically,the shampoo-treated hair tresses, as described in the wet-combabilitytest further above, are air-dried and then complexed with dye solution.After rinsing off the free dye molecules and squeezing off excess water,the dye molecules bound by the hair tresses are then extracted from thehair by a solution of 50 volume percent of isopropanol and 50 volumepercent of de-ionized water. An UV Spectrometer is used to detect thedye concentration of the extracted solution at 533 nm. The micro-gramdye per gram hair is calculated.

When the shampoo composition comprises 0.5 percent of the celluloseether derivative of Example 17 having a HS of 0.006, from 107 to 118microgram dye per gram hair is detected on the hair that has beentreated from 1 to 15 times with shampoo. When the shampoo compositioncomprises 0.5 percent of the cellulose ether derivative of ComparativeExample A having a HS of 0.000, from 37 to 48 microgram dye per gramhair is detected on the hair that has been treated from 1 to 15 timeswith shampoo.

These results illustrate the higher substantivity of the cellulose etherderivatives of the present invention as compared to correspondingcellulose ether derivatives comprising a cationic substituent but nohydrophobic substituent. However, the increased amount of dye on thehair does not change with multiple shampoo treatments, illustrating thatthe cellulose ether derivatives of the present invention do not resultin undesirable build up.

E. Preparation of the Hydroxyethyl Celluloses of Examples 22-24

A reaction vessel equipped with a stirrer, condenser, addition funnels,and nitrogen supply is charged with HEC-1 and with isopropyl alcohol andwater in the amounts listed in Table 7 below. After purging withnitrogen, a 25 percent aqueous sodium hydroxide solution is added. Theweight of sodium hydroxide, calculated as pure product, is listed inTable 7 below. After stirring for 30 minutes, Q342 is added. Its weight,calculated as undiluted 3-chloro-2-hydroxypropyldodecyldimethyl ammoniumchloride is listed in Table 7 below. The reaction mixture is heated to55° C. and held there for 60 to 90 minutes. While the reaction mixtureis kept at 55° C., Q151 is added. Its weight, calculated as undiluted2,3-epoxypropyltrimethyl ammonium chloride, is listed in Table 7 below.After heating for another 90 to 120 minutes (for a total cook out timeof 180 minutes), the reaction mixture is cooled and neutralized wit 2.2g acetic acid. The reaction slurry is filtered, washed and dried asdescribed in Examples 1-21 above.

TABLE 7 Production of the cellulose ether derivatives 22–24 Exam- GramsGrams Grams Grams Grams Grams ple NaOH Q151 Q342 IPA distilled water HEC22 2.73 16.0 1.3 360 77 80 23 1.77 9.8 1.5 226 47 50 24 3.15 15.4 4.8365 72 80

TABLE 8 Properties of the produced cellulose ether derivatives 22–24(Comp.) SFSO deposition Example % N HS* CS 1% viscosity (ppm) 22 0.950.0025 0.20 2720 21.0 23 0.96 0.005 0.20 2700 19.9 24 0.96 0.010 0.202800 18.0 *Calculated based on efficiencies of reference reactions asdescribed above

F. Evaluation Method for Sunflower Seed Oil Deposition from Body WashFormulations

Sunflower seed oil is commonly used as a skin moisturizing agent in bodywash formulations. The study on deposition of sunflower seed oil is doneon vitro skin. Sunflower seed oil is a natural triglyceride withdifferent carbon chair lengths. The oil is derivatized to form methylesters for Gas Chromatography analysis. Linoleic acid is the majorcomponent of sunflower seed oil and used as the indicator. The linoleicacid is measured by GC analysis. A fixed dimension of skin (3 cm×6 cm)is treated with 0.15 gram of a body wash formulation. The treatmentincludes 30 seconds of product application followed by 15 seconds ofrinsing with water at a flow rate of 1 liter/minute. The body washformulation comprises 11 percent sodium laurylether sulfate, 4 percentcocamidopropyl betaine, 1.5 percent sodium chloride, 15 percentsunflower seed oil and 0.5 percent of the cellulose ether listed inTable 8 and water making a total of 100 percent. Table 8 illustratesthat body wash formulations comprising a cellulose ether of the presentinvention exhibit a good sun flower seed oil deposition.

1. A personal care composition, comprising: hydroxyethyl cellulose etherhaving from 6,000 to 8,000 anhydroglucose repeat units, comprising onthe average from 1.0 to 3.0 moles of hydroxyethyl groups, per mole ofanhydroglucose unit, and being substituted with (a) on the average from0.0005 to 0.05 moles, per mole of anhydroglucose unit, of a substituentof the formula I:R¹R²R³R⁴N⁺(A^(z−))_(1/z)  (I)  wherein R^(l) and R² each independentlyare —CH₃, R³ is —CH₂—CHOH—CH²⁻, R⁴ is a dodecyl group, and A^(z−) is ananion, and z is 1; and (b) on the average from 0.15 to 0.35 moles, permole of anhydroglucose unit, of a substituent having the formula II:[R⁵R⁶R⁷R^(B)IC⁺](A^(z−))_(1/z),  (II)  wherein R⁵, R⁶ and R⁷ eachindependently are —CH₃, R⁸ is —CH₂—CHOH—CH²⁻, A^(z−) is an anion, and zis 1; and a personal care ingredient, comprising eucalyptus oil ormenthol.